Lodging is one of the main factors limiting the further improvement of wheat yield. Stem strength is an important indicator for determining wheat lodging resistance. In order to identify the locus for stem strength, in this paper, Annong0711 (stronger stem strength and lodging resistance) and Henong825 (weaker stem strength and lodging resistance) were used as parents to construct a RIL population and their stem strength phenotypes were determined in 2017. Using SSR markers, the locus controlling stem strength (designated Qss.ahau-3B) was preliminarily mapped in the interval of wmc231-barc248 on chromosome 3B, with the physical distance of 68-162 Mb. Thirteen CAPS markers were further developed to shorten the locus Qss.ahau-3B to Ex-6650-barc248 (150-162 Mb) based on the SNPs in the target region from the Wheat 660K Chip through scanning the two parents and two bulks. The results provide a useful theoretical basis for fine-mapping of the target locus and cloning of candidate genes.